Some months back, while roaming Berlin's famous "Kaufhaus des Westens" - an over-glorified shopping mall - my friends and I had a little contest about who could find the most expensive bottle of wine within 2 two minutes. Although I don't remember who won - which means it probably wasn't me - I remember the winning wine costing more than a thousand Euros (which feels like 50 billion $US these days). A price tag like that makes me wonder: How big of a difference does quality in wine really make? Is there a real 985$ difference in taste between the 1000$ wine and a comparable 15$ wine?

Sure, I can taste the difference between a Riesling and a Burgunder, but I've never fooled myself into believing I could discern the quality of a wine with my taste buds alone. Also, I've always been somewhat skeptical about gourmet tasters who convince us they can indeed taste qualitative differences.

So this is where a truly fascinating experiment comes into play that reminded me that "taste" is more than a matter of taste:The experiment I refer to here was conducted in 2007 by a group of researchers around Hilke Plassmann from the California Institute of Technology. It involved a couple of bottles of Cabernet Sauvignon and the Stanford wine tasting group:For their experiment, Plassmann and her colleagues told their participants that they would be tasting five different wines in order to test time differences in taste perception for different flavors. In reality, however, the researchers were interested in something else; namely the connection between perceived tastiness and the taster's knowledge of a wine's price.

To get at this relation between price and taste experience, the researchers first made sure the experiment participants were always given information of a wine's supposed price. They did this by presenting the wines for the experiment in bottles that were clearly identified by their supposed retail prices of ($5 to $90).

What they also did, was refill the wines in such a way that each participant would have to taste the same wine twice; once from a bottle that was supposedly expensive (e.g. $90) and once from a bottle that had a much lower price tag (e.g.$10). Every participant was therefore led to believe that he or she was tasting five different wines, when indeed he or she was only tasting three different wines; two of them twice.

The first set of results is striking, albeit possibly what you would expect: The expert wine tasters remained oblivious to the researcher's manipulations and were not able to tell that they were tasting only three, instead of five, wines. Also, when tasting the same wine, the participating wine tasters systematically reported superior taste for the wine that came out of the $90 bottle, in contrast to the wine that came from the $10 bottle.

So are experienced wine tasters trying to fool the less taste discerning public? At first sight these results seem to suggest just that, but the experiment provides some further data, which makes the story more interesting still:

Since reported tastiness is a poor measure of true taste experience in the era of fMRI scanning machines, the researchers were careful enough to take a peek into their participant's brains as these tasted the wines, and found something fairly surprising: When tasting the wine out of the $10 bottle, the medial orbitofrontal cortex - an area of the brain that is strongly related to experiences of pleasure - showed only very little activity. When the exact same wine was poured out of a $90 bottle however, this brain area showed levels of activation which indicate that the participants were indeed drawing much more enjoyment from the same wine this time around. In other words, the price tag seemed to have a real physiological influence on the taster's taste experience.

To understand what really seems to be happening here, one needs to have a little more understanding of how the brain operates. For example, although the medial orbitofrontal cortex is correlated with deriving pleasure from tastes, odor and even music, it is not the brains primary taste area (which would be the insula cortex, the ventroposterior medial nucleus of the thalamus, or the prabrachial nuclei of the pons). Interestingly enough, the primary taste areas show no significant differences in activation for the different experimental conditions. This offers the interpretation that the participant's taste experience is a combination of the actual sensory input as well as the participant's taste expectations. In the experiment the price tag seemed to awaken expectations that were sufficient to influence the resulting overall taste experience to cause what is essentially a Placebo effect. Participant's expected the wine to taste better, and subsequently it actually did taste better. It is a similar finding to the one featured on Dan Ariely's predictably irrational site, but adds some neurological data to the storyline. It is also something I believe all of us have experienced in our own lives: We unknowingly taste a food we are convinced we do not like, but the dish tastes nice to us. In this situation, not knowing what we were eating means we do not have negative expectations interfering with the sensory taste experience; thus allowing us to actually enjoy the previously disliked food product.The study should be appealing to a wide demographic: Parents who want to trick children into eating their vegetables ("these are green French fries!"), or marketers who want to convince you that you are buying a truly superior product ("Look! It costs $500 it must be great"). Indeed, I have considered setting myself apart from the other bloggers out there by charging a nominal fee for reading my posts, but something tells me that this wouldn't fly...

Is the Stanford Wine Tasting group really composed of experts? Or is it, like many other affinity groups on college campuses, composed of people who are the very definition of amateurs--those who have a particular love for their subject.

I ask because other studies that seem to show that people generally are fooled by the price of wine also show that the true professionals--wine buyers, sommaliers, vintners, etc--are not led astray by a higher stated bottle price.

To the experts comment: I would make an educated guess that if 'true' experts were indeed tested, they would have less activity in the orbitofrontal cortex. I suspect that as seniority, experience, and expertise develop in a certain area (this one being wine tasting) individuals are less influenced by external variables (the price of wine), and more reliant on their own judgement (did I just taste the same wine twice!?).

Either way, I think the main point isn't specifically about the wine. The fact that we have the physiological capacity to affect the outcome of our own experiences is very empowering. And I for one find it encouraging! :)

Since my own research is related to the study, I guess I should stay active in this comment thread: I think the main point is that there is a neurological effect of "marketing"; i.e. of price information. This is very much in line with all of what we know about how the brain interprets the sensory input it receives: It is a bi-direcitonal process in which top-down, as well as bottom-up information processing takes place. For the effect to be clearly distinguishable there needs to be a certain degree of ambiguity in the information being assessed. This would speak towards your hypothesis that true experts would not exhibit the effect, since supposedly they would be sampling much more true taste information from the wine. (as a side note, from my reading, I'd argue that what makes an expert is the efficiency of integrating large amounts of data - not necessarily the ability to require less external information).
Alternatively, however, experts may be particular prone to the effect if e.g. there is a strong element of learning involved or if dissonance theory plays a role (an expert expects that she will prefer the expensive wine, the lay person does not necessarily expect this of herself). It would be interesting to see how expertise moderates the effect.